Hello “Aunt Flo”

“Aunt Flo’s Coming to Town,” “Shark Week,” “Cousin Red,” “Ride the Cotton Pony”…..are we talking bad late night TV? No ladies, it’s that time of the month aka your menstrual period. If you are a middle school girl in the US (or are deeply involved in caring for such a creature), then having some idea of when this momentous event will take place in your household may be helpful. A lot has been made of the trend towards earlier onset of puberty in the U.S. and other developed countries.

Unfortunately good records for pubertal development are not available going back hundreds of years, so theories that the age of menarche has dropped dramatically (from say, 17 to 13 years of age) are mostly speculation. The average age of menarche (the technical term for your first period-pronounced MEN-are-kee) when using good data over the past 50 or so years, does indeed show a decline, but only by a few months, and is likely due to the overall better nutrition and higher rates of obesity in our prosperous nations.

The Timing of Puberty

While the majority of pubertal timing is determined by genetics, we can’t ignore the possible role of environmental factors that may be leading to early maturity. Other known risk factors for early puberty include obesity, inactivity, smoking/second-hand smoke and psychological stress. Researchers have moved away from thinking that puberty starts when a critical weight is reached, and now believe it’s a significant body fat percentage that triggers maturation.

Obviously, the start of puberty is complicated, and there is very little that can be controlled about how and when it happens. Compared to a lot of other systems in the human organism, the “switch” that turns on puberty is unknown. Puberty is still a profoundly mysterious process involving ancient areas of the brain synthesizing information from both inside and outside of the body to change a girl into a woman at (questionably) just the right time!

It’s common to think of a girl’s first period as the start of puberty, but menarche is one of the later milestones in the process. One of the first visible signs of puberty is breast development or “breast budding”, and any suggestion of this before eight years in a girl should be investigated, as that could be abnormal. We do know that different races mature differently: African-American girls show the first signs of puberty at earlier ages than Caucasian or Hispanic girls, and Asian girls develop later.

In addition to breast growth, the appearance of underarm hair, pubic hair and then a growth spurt, are all things that happen (usually, but not always in that order) before the first period shows up, which is about two years after the start of breast budding. The average age for starting periods in the U.S. is roughly 12 1/2, but what falls into the normal range is anything from 11 to 14 years old. For girls (and their families) on the early end of the spectrum, it can be tough to adjust to a woman’s body when her life is still completely about being a child. For girls on the later end of the spectrum, waiting for her period to start can feel like an eternity, and she can become anxious that something is wrong.

Early Puberty

In the case of early signs of puberty, it’s just the luck of the genetic draw mixed with her particular environment, and most of these cases are not treated with anything other than reassurance. Cases, where something abnormal and/or treatable is discovered, can include such rare things as ovarian or brain tumors (or other central nervous system damage), genetic syndromes that include precocious puberty (the technical term for abnormally early puberty), or metabolic problems that lead to abnormal levels of hormone production.

Evaluating a girl with early puberty involves a physical exam, blood work, a special X-ray of the arm and hand to give a “bone age” that can be compared her chronologic age, a pelvic ultrasound (NOT done vaginally but with a full bladder), and a very thorough review of her history and growth curves. Other, more specialized tests could include a brain MRI or stimulation tests, where a particular hormone is given, and then blood levels are checked at certain times afterward.

If nothing abnormal or otherwise treatable is discovered, but the child is determined to have early puberty, then she may be a candidate for an injectable treatment that can turn off the pubertal process. This allows her to catch up on some growth (which slows to almost nothing once menarche hits), and provides some more time for her to mature before having to deal with puberty.

Late Puberty

While most parents pray for a “late bloomer”, girls without any signs of puberty by age 14 or who have gone more than five years without starting their period since the breast development began need to be evaluated for delayed puberty. In fact, parents or pediatricians don’t need to wait that long to check on the status of delayed puberty if the girl is anxious. Most of the time, it’s just a matter of waiting for just a little longer and, voila, the cycle starts. By age 15, only about 2% of girls will not have started their periods, so by that time, being a little worried is justified.

The evaluation for delayed puberty is very similar to that described above for early puberty. Possible reasons for this could include disordered eating (anorexia nervosa/bulimia), metabolic problems related to diabetes (such as polycystic ovarian syndrome), early menopausal syndromes (which are common in girls who are cancer survivors), or rare anomalies of the reproductive organs. Treatments will vary, depending on the cause, but most will involve some hormone replacement, to get the body to develop, have periods and get back on the developmental track.

Celebrate Puberty

Believe it or not, doctors treat “having a period” as a vital sign, like having a normal blood pressure or not having a fever; a regular, predictable menstrual period is part of being a healthy woman. So whether it’s early, late or right on time, it’s something to be anticipated and appreciated!